The NIH Inter-Institute Endocrinology Fellowship Program provides a comprehensive training experience that involves many of the NIH clinical branches working in endocrinology, as well as the Georgetown University Hospital, Washington Hospital Center and Walter Reed Army Medical Center. The basic and clinical endocrine research facilities at the NIH are among the most extensive and highly regarded in the world. Thus the fellowship is ideal for physicians who seek a broad education in both research and clinical endocrinology. Clinical training occurs largely in the first year. The remaining two years are spent primarily in laboratory or clinical research under the direction of a senior investigator in one of the several endocrinology branches of the NIH. During this research period, active clinical experience continues through a weekly continuity outpatient clinic, consult service and participation in clinical conferences. The National Institute of Diabetes and Digestive and Kidney Diseases (Diabetes Branch, Metabolic Diseases Branch, Clinical Endocrinology Branch and the Islet Autoimmunity Branch);The National Institute of Child Health and Human Development (Developmental Endocrinology Branch, Reproductive Biology and Medicine Branch);and The National Institute of Dental and Craniofacial Research participate in this program. Fellows are responsible for five to ten patients, at any one time on the inpatient service of the NIH. The trainee has total responsibility for all aspects of the patient's care, under the supervision of the endocrine faculty. Fellows make daily rounds, discuss patients with the attending physicians, and participate in management decisions related to both patient care and clinical investigation. Although all patients are admitted under peer-reviewed research protocols, there are many other aspects of diagnosis and patient care that fall completely under the discretion of the endocrine fellows. In addition, fellows on the endocrine service serve as consultants to the rest of the Clinical Center, where patients are unselected with regard to endocrine problems. Thus, the fellows gain experience with a number of common problems of endocrine disease that may occur in any general medical ward. Clinical research activities include programs in all the areas of endocrine and metabolic diseases. Study design, outcome measures statistical analysis and ethical and regulatory issues are stressed.